These include nitrogen dioxide, ozone, formaldehyde, sulphur dioxide, methane and carbon monoxide. All affect the air we breathe and therefore our health, and a number of them also play a role in climate change.

The “Precursor” in the spacecraft’s name references the fact that the TROPOMI instrument comes before a near-identical sensor that will eventually fly on Europe’s next-generation weather satellites from 2021.

Putting up 5P now also ensures there is no data gap in observations should an ageing, previous-generation instrument suddenly fail. That sensor, called OMI, flies on the US space agency’s Aura satellite.

Although still in good health, it is operating far beyond its design lifetime. But TROPOMI is more than just a gap-filler, says KNMI’s principal investigator Pepijn Veefkind because it is a step on in performance with a tenfold improvement in resolution on what has gone before.

“Big sources, such as power plants – you will be able to detect them. But generally we will be on the city scale. So for example in the Netherlands, we will be able to distinguish between the centre of Rotterdam and the harbour,” he told BBC News.

One major use for the data will be in delivering air quality forecasts, including providing warnings when citizens are likely to encounter problems like smog or high UV (ultraviolet light) levels.

Image copyright ESA

Image caption
The top of the Rockot vehicle. S5P is encapsulated under a protective fairing

British atmospheric scientist Dr Paul Palmer said some of TROPOMI’s climate observations would be just as important, and highlighted its detection of the greenhouse gas methane.

“It’s kind of the poorer cousin of carbon dioxide, but it has a fascinating story of its own,” the Edinburgh University researcher explained.

“In the 1990s its growth rate in the atmosphere went to zero for seven years before then going back up – and we don’t know why. The quality of the data has not been sufficient for us to say why that happened; and that’s a big problem.

“Having the daily information from TROPOMI, I’m hopeful that if something similar happens again we’ll be in a better position to explain what’s going on.”

UK Space Agency Chief Executive, Graham Turnock, said the Copernicus programme had been a fantastic success story for the UK.

“It has a global vision and provides near real-time measurements of Earth on an unprecedented scale – and we’ve been a key part of it.

“It’s been a major work programme for UK space technology companies, but data from the Sentinel satellites is why Copernicus exists – data that benefits the UK in areas such as emergency response, flooding, farming, environmental management, rural payments, air quality, marine planning, (and) fisheries.”

Prime Minister Theresa May was committed to collaboration with European partners on science and technology, he added.

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Media captionPepijn Veefkind: “TROPOMI breaks the reflected light up into thousands of colours”